package server;

import classload.MyClassLoad;
import mapper.MyContext;
import mapper.MyHost;
import mapper.MyMapper;
import mapper.MyWrapper;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.Node;
import org.dom4j.io.SAXReader;

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.concurrent.*;

/**
 * Minicat的主类
 */
public class Bootstrap {

    /**
     * 定义socket监听的端口号
     */
    private int port = 8080;

    /**
     * 模拟部署的结构
     */
    private MyMapper myMapper;

    public int getPort() {
        return port;
    }

    public void setPort(int port) {
        this.port = port;
    }


    /**
     * Minicat启动需要初始化展开的一些操作
     */
    public void start() throws Exception {

        // 加载解析相关的配置，web.xml
        // loadServlet();

        // 加载部署结构
        loadMyMapper();

        // 定义一个线程池
        int corePoolSize = 10;
        int maximumPoolSize = 50;
        long keepAliveTime = 100L;
        TimeUnit unit = TimeUnit.SECONDS;
        BlockingQueue<Runnable> workQueue = new ArrayBlockingQueue<>(50);
        ThreadFactory threadFactory = Executors.defaultThreadFactory();
        RejectedExecutionHandler handler = new ThreadPoolExecutor.AbortPolicy();


        ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(
                corePoolSize,
                maximumPoolSize,
                keepAliveTime,
                unit,
                workQueue,
                threadFactory,
                handler
        );





        /*
            完成Minicat 1.0版本
            需求：浏览器请求http://localhost:8080,返回一个固定的字符串到页面"Hello Minicat!"
         */
        ServerSocket serverSocket = new ServerSocket(port);
        System.out.println("=====>>>Minicat start on port：" + port);

        /*while(true) {
            Socket socket = serverSocket.accept();
            // 有了socket，接收到请求，获取输出流
            OutputStream outputStream = socket.getOutputStream();
            String data = "Hello Minicat!";
            String responseText = HttpProtocolUtil.getHttpHeader200(data.getBytes().length) + data;
            outputStream.write(responseText.getBytes());
            socket.close();
        }*/


        /**
         * 完成Minicat 2.0版本
         * 需求：封装Request和Response对象，返回html静态资源文件
         */
        /*while(true) {
            Socket socket = serverSocket.accept();
            InputStream inputStream = socket.getInputStream();

            // 封装Request对象和Response对象
            Request request = new Request(inputStream);
            Response response = new Response(socket.getOutputStream());

            response.outputHtml(request.getUrl());
            socket.close();

        }*/


        /**
         * 完成Minicat 3.0版本
         * 需求：可以请求动态资源（Servlet）
         */
        /*while(true) {
            Socket socket = serverSocket.accept();
            InputStream inputStream = socket.getInputStream();

            // 封装Request对象和Response对象
            Request request = new Request(inputStream);
            Response response = new Response(socket.getOutputStream());

            // 静态资源处理
            if(servletMap.get(request.getUrl()) == null) {
                response.outputHtml(request.getUrl());
            }else{
                // 动态资源servlet请求
                HttpServlet httpServlet = servletMap.get(request.getUrl());
                httpServlet.service(request,response);
            }
            socket.close();

        }
*/

        /*
            多线程改造（不使用线程池）
         */
        /*while(true) {
            Socket socket = serverSocket.accept();
            RequestProcessor requestProcessor = new RequestProcessor(socket,servletMap);
            requestProcessor.start();
        }*/


        System.out.println("=========>>>>>>使用线程池进行多线程改造");
        /*
            多线程改造（使用线程池）
         */
        while (true) {

            Socket socket = serverSocket.accept();
            RequestProcessor requestProcessor = new RequestProcessor(socket, myMapper);
            //requestProcessor.start();
            threadPoolExecutor.execute(requestProcessor);
        }


    }

    /**
     * 解析 server.xml 初始化 MyMapper
     */
    private void loadMyMapper() {
        if (Objects.nonNull(myMapper)){
            return;
        }
        myMapper = new MyMapper();
        InputStream resourceAsStream = this.getClass().getClassLoader().getResourceAsStream("server.xml");
        SAXReader saxReader = new SAXReader();

        try {
            Document document = saxReader.read(resourceAsStream);
            Element rootElement = document.getRootElement();

            // port 端口
            List<Element> selectNodes = rootElement.selectNodes("//connector");
            Element port = selectNodes.get(0);
            String portValue = port.attributeValue("port");
            this.port = Integer.valueOf(portValue);

            // host
            List<Element> selectHostNodes = rootElement.selectNodes("//host");
            Element host = selectHostNodes.get(0);
            String hostName = host.attributeValue("name");
            myMapper.setHostName(hostName);

            MyHost myHost = new MyHost();
            myMapper.setMyHost(myHost);


            // webapps
            String appBase = host.attributeValue("appBase");

            myMapper.setAppBase(appBase);


            // 开始扫描解析 webapps 下的路径
            File file = new File(appBase);
            File[] files = file.listFiles(new FileFilter() {
                @Override
                public boolean accept(File pathname) {
                    // 文件夹类型
                    return pathname.isDirectory();
                }
            });

            Map<String, MyContext> myContextMap = new HashMap<>();
            myHost.setMyContextMap(myContextMap);
            for (int j = 0; j < files.length; j++) {
                MyContext myContext = new MyContext();
                String name = files[j].getName();
                myContextMap.put(name, myContext);
                String absolutePath = files[j].getAbsolutePath();
                myContext.setContextPath(absolutePath);
                // 设置应用关联的自定义的 类加载器
                MyClassLoad myClassLoad = new MyClassLoad();
                myClassLoad.setPath(absolutePath);
                myContext.setMyClassLoad(myClassLoad);

                Map<String, Servlet> stringServletMap = loadServlet(absolutePath,myClassLoad);
                Map<String, MyWrapper> myWrapperMap = new HashMap<>();
                myContext.setMyWrapperMap(myWrapperMap);
                stringServletMap.forEach((k, v) -> {
                    MyWrapper myWrapper = new MyWrapper();
                    myWrapper.setServlet(v);
                    myWrapperMap.put(k, myWrapper);
                });
            }


        } catch (DocumentException e) {
            e.printStackTrace();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }


    private Map<String, HttpServlet> servletMap = new HashMap<String, HttpServlet>();

    /**
     * 加载解析web.xml，初始化Servlet
     */
    private Map<String, Servlet> loadServlet(String path, MyClassLoad myClassLoad) throws FileNotFoundException {

        InputStream resourceAsStream = new FileInputStream(new File(path + "/web.xml"));
        SAXReader saxReader = new SAXReader();

        HashMap<String, Servlet> stringServletHashMap = new HashMap<>();
        try {
            Document document = saxReader.read(resourceAsStream);
            Element rootElement = document.getRootElement();

            List<Element> selectNodes = rootElement.selectNodes("//servlet");
            for (int i = 0; i < selectNodes.size(); i++) {
                Element element = selectNodes.get(i);
                // <servlet-name>lagou</servlet-name>
                Element servletnameElement = (Element) element.selectSingleNode("servlet-name");
                String servletName = servletnameElement.getStringValue();
                // <servlet-class>server.LagouServlet</servlet-class>
                Element servletclassElement = (Element) element.selectSingleNode("servlet-class");
                String servletClass = servletclassElement.getStringValue();

                // 根据servlet-name的值找到url-pattern
                Element servletMapping = (Element) rootElement.selectSingleNode("/web-app/servlet-mapping[servlet-name='" + servletName + "']");
                // /lagou
                String urlPattern = servletMapping.selectSingleNode("url-pattern").getStringValue();
                // 加载磁盘的.class
                Class<?> loadClass = myClassLoad.loadClass(servletClass);
                stringServletHashMap.put(urlPattern, (Servlet) loadClass.newInstance());

            }


        } catch (DocumentException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        return stringServletHashMap;
    }


    /**
     * Minicat 的程序启动入口
     *
     * @param args
     */
    public static void main(String[] args) {
        Bootstrap bootstrap = new Bootstrap();
        try {
            // 启动Minicat
            bootstrap.start();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
